docs: def main():
      '''Calculate the depth of a liquid in centimeters using a HCSR04 sensor
         and a Raspberry Pi'''
  
      trig_pin = 17
      echo_pin = 27
  
      # Default values
      # unit = 'metric'
      # temperature = 20
      # round_to = 1
  
      hole_depth = 80  # centimeters
  
      # Create a distance reading with the hcsr04 sensor module
  
      value = sensor.Measurement(trig_pin,
                                 echo_pin
                                 )
  
      raw_measurement = value.raw_distance()
  
      # To overide default values you can pass the following to value
      # value = sensor.Measurement(trig_pin,
      #                            echo_pin,
      #                            temperature=10,
      #                            round_to=2
      #                            )
  
      # Calculate the liquid depth, in centimeters, of a hole filled
      # with liquid
      liquid_depth = value.depth_metric(raw_measurement, hole_depth)
      print("Depth = {} centimeters".format(liquid_depth))